1. Field of the Invention
The present invention relates to a facsimile apparatus, to which a telephone can be connected, a control method thereof, and a storage medium.
2. Description of the Related Art
A facsimile apparatus, which can connect a telephone, has an automatic switching function between FAX reception and an operation of the telephone upon reception of an incoming call. This function is classified into two types depending on whether a telephone to be connected has a telephone answering function. One type is “FAX/telephone answering automatic switching” in case of a telephone with a telephone answering function. With this function, while an answering telephone performs automatic answering upon reception of an incoming call, the facsimile apparatus monitors a telephone line using a modem, and starts FAX reception if a FAX incoming call is detected. The other type is “FAX/TEL automatic switching” in case of a telephone without any telephone answering function. With this function, the facsimile apparatus responds upon reception of an incoming call, and causes a telephone to ring so as to call for the user, similarly monitors a telephone line using a modem, and starts FAX reception if a FAX incoming call is detected.
In either case, in order to judge FAX reception by monitoring the telephone line, a tone signal called a calling signal (CNG), which is output from the transmitting device side at the time of FAX transmission is used. The facsimile apparatus can detect the CNG by the modem, and can judge that a partner is not a person but a FAX when this CNG is detected. Therefore, in order to automatically switch between a telephone operation and FAX reception without any malfunction, it is impermissible to erroneously detect the CNG. Japanese Patent Laid-Open No. 11-32192 has proposed a method of preventing misrecognition of a human voice (speech) as the CNG by checking a frequency or cadence. With this method, patent literature 1 prevents a 1100-Hz component which is included in speech and is the same as the CNG from being misrecognized as the CNG.
However, the aforementioned related art suffers problems to be described below. For example, when the FAX/telephone answering automatic switching function is set, the user may off-hook a receiver of the answering telephone simultaneously with an incoming call or may unintentionally off-hook the receiver during telephone answering when a loudspeaker of the answering telephone is OFF. At this time, when the user executes pulse-dialing to originate a call, noise is generated by pulse-dialing on a telephone line, and the facsimile apparatus misrecognizes that noise as the CNG to automatically start FAX reception.
In the “FAX/TEL automatic switching” function, an outgoing message (OGM) like “Now calling. Please wait” is often output onto a telephone line so as to inform a caller of calling when the partner side is a person. This OGM is output not by the telephone but by the facsimile apparatus. That is, since the OGM is controlled on the facsimile apparatus side, an output timing of the OGM onto the telephone line can be detected. On the other hand, in the “FAX/telephone answering automatic switching” function, the answering telephone outputs the OGM for telephone answering onto a telephone line. For this reason, the facsimile apparatus cannot detect the OGM output timing onto a line. Therefore, the facsimile apparatus has to detect even the CNG which is output to be superposed on the OGM. Under such conditions, when the CNG misrecognition prevention method of the related art is used, the CNG detectability is considerably impaired.